Understanding child mental health service systems necessitates a comprehensive examination of patterns of service utilization, including service career paths, costs, service needs and access barriers. This study of children 9-17 years of age (N=1260), drawn from one, large heterogeneous county north of New York City, entails such an examination from a multidimensional perspective, incorporating three levels of analysis: the individual child and primary caregivers, the service system and the social/geographic area. The study will: (1) survey children and their primary caregivers in five service systems: mental health; juvenile justice; child welfare, special education, and substance use; (2) incorporate the data gathered by the Columbia University-NYSPI Child Methodologic Epidemiologic Catchment Area (ECA) project; (3) survey a contemporaneous community probability sample and; (4) supplement the individual survey findings with teacher interviews (of children 9-11 yrs. of age) and with medical record information. Data collected from a survey of providers and agency directors will yield information on organizational factors such as referral and case management practices that can either facilitate or impede the delivery of services. Small area techniques will be applied as a means of elucidating geographic influences on service use, needs and barriers. Based on our analyses, we will then specify the parameters of a model of service use that incorporates the individual, provider, and area data and the interactions among these factors. Examining this information in an integrated, comprehensive manner is essential for improved mental health planning and policy making, and we will apply the model to estimate the effects of policy options on child mental health service use. We have a PAL agreement with the NYS Office of Mental Health and an Expert Advisory Board has been assembled for the purpose of: (1) facilitating our understanding of these complex data; (2) establishing a way for child mental health policy makers to interact with academic researchers in matters of mutual concern, and; (3) providing a mechanism for making our research findings available to those in a position to utilize them.